Body Controller Fault Diagnosis (Chevrolet Captiva 1)

Diagnostic System Check - Vehicle

1. Before proceeding with diagnostics, it is necessary to make sure that none of the following preliminary inspections/checks will reveal the cause of the vehicle malfunction.

• Make sure the battery is fully charged
• Make sure the battery cables are clean and the fasteners are tight.
• Check for blown fuses
• Make sure the ground wires are clean, the fasteners are tight, and the ground wires are connected correctly.
• Inspect easily accessible systems or visible parts of systems for obvious signs of damage or conditions that could lead to malfunction.
• Inspect for aftermarket equipment that may affect system operation.
• Find service bulletins related to your issue.

2. Install the diagnostic tool. Make sure the diagnostic tool has power.

3. Turn on the ignition, turn off the engine, check the connection with all controllers on the car.

Important: Open the driver's door to prevent activation of the Auxiliary Power Hold (RAP) mode during this check. During this check, you can start the engine. Turn off the engine as soon as the power mode is checked when starting the engine.

4. Using a scan tool, access the Body Control Module Power Mode parameter list. Verify that all parameters listed in the following table correspond to the ignition switch position. The following PMM Power Mode parameter table illustrates the correct state of these parameters (circuits) at the corresponding ignition switch positions. The circuits corresponding to the parameters are indicated in parentheses.



5. Turn on ignition, observe security indicator. Security indicator should remain on after vehicle bulb check is completed.

6. Try to start the engine. Make sure that the engine turns over.

7. Attempt to start the engine. Make sure that the engine starts and runs.

Important: Do not clear any DTCs unless instructed to do so in the diagnostic procedure description.

Important: If any DTCs are powertrain related, select "Collect Information" to save the DTC information using the scan tool.

PMM Power Mode Parameters

Ignition switch position	Current power supply mode	Ignition Off/Run/Start (off/run/start voltage circuits)	Auxiliary ignition/Start (auxiliary voltage circuit)	Ignition run/start (voltage circuit "Ignition 1")
Off, key removed	Off	Key removed/auxiliary	Inactive	Inactive
Off, key inserted (LOCK - locked)	Off	Key in/out	Inactive	Inactive
ACC	Auxiliary	Key inserted/ACC (auxiliary)	Active	Inactive
ON	Job	Job	Active	Active
START	Launch request	Start (cranking)	Inactive	Active

List of Diagnostic Trouble Codes (DTC)

DTC code	Description	SUBSYSTEM
B0283	Rear window heating circuit	HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
B0981	Short circuit to ground of winter mode switch of gearbox	POWER POINT
B1000	Functioning of the electronic control unit (ECU), malfunction of the special memory	DESIGN
B1000	Electronic Control Unit (ECU) Functionality, RAM Integrity	DESIGN
B1000	Electronic Control Unit (ECU) Functionality, ROM Integrity	DESIGN
B1000	Electronic Control Unit (ECU) Functionality, EPROM Integrity	DESIGN
B1001	Option configuration error - option not programmed	DESIGN
B1016	VIN not programmed	DESIGN
B1370	Ignition circuit short circuit 1 device (ON and START) on battery voltage	DESIGN
B1370	Ignition circuit short circuit 1 device (ON and START) to ground or open circuit	DESIGN
B1380	Short circuit of ignition circuit of AUXILIARY device to battery voltage	DESIGN
B1380	AUXILIARY device ignition circuit shorted to ground or open circuit	DESIGN
B1395	Device Reference Voltage Circuit at Output 1 - Voltage Below Threshold	LIGHTING SYSTEM
B1395	Device Reference Voltage Circuit at Output 1 - Voltage Above Threshold	LIGHTING SYSTEM
B1428	Ignition Power Switch Relay 1 Circuit	DESIGN
B1433	Ignition Power Switch Relay 2 Circuit	DESIGN
B1440	Mismatch of the input circuits of the master device of the power supply mode	DESIGN
B1441	Closing the ignition circuits of the device OFF, OPERATION and START to battery voltage.	DESIGN
B1441	Short circuit of ignition circuits of the device OFF, OPERATION and START to ground or open circuit.	DESIGN
B1475	Auxiliary power hold circuit	DESIGN
B1480	Battery discharge protection circuit	CHARGING SYSTEM
B1517	Battery voltage below threshold	CHARGING SYSTEM
B1517	Battery voltage is above threshold	CHARGING SYSTEM
B2530	Front fog lamp control circuit	LIGHTING SYSTEM
B2545	Reverse Light Chain	LIGHTING SYSTEM
B2575	Headlight control circuit	LIGHTING SYSTEM
B257A	Headlight switch input signal mismatch	LIGHTING SYSTEM
B2580	Headlight high beam control circuit	LIGHTING SYSTEM
B2585	Left parking light control circuit	LIGHTING SYSTEM
B2625	Pulse Width Modulation (PWM) output circuit for display illumination control	LIGHTING SYSTEM
B2645	The voltage in the ambient light sensor circuit is below the threshold	LIGHTING SYSTEM
B2645	The voltage in the ambient light sensor circuit is above the threshold	LIGHTING SYSTEM
B2705	Shorting the gearshift release circuit to ground	POWER POINT
B2745	Traction control switch circuit shorted to ground	CHASSIS
B2750	Horn relay winding circuit	AUXILIARY
B2924	Anti-theft alarm sensor 3 signal circuit (tilt, etc.)	anti-theft system
B3089	Anti-theft alarm sensor 1 signal circuit (concussion, penetration, etc.)	anti-theft system
B3130	All door unlocking chain	AUXILIARY
B3135	All door locking chain	AUXILIARY
B3265	Trunk/Tailgate/Window Release Output Circuit	AUXILIARY
B3445	Brake light chain	LIGHTING SYSTEM
B3622	Steering Wheel Controls Signal Circuit Group 1 Voltage Above Threshold	DESIGN
B370C	Rain Sensor Intensity Signal Circuit	WINDSHIELD WIPERS AND WASHERS
B370D	Rain sensor mode control circuit	WINDSHIELD WIPERS AND WASHERS
B3715	Front Wiper Relay Control Circuit	WINDSHIELD WIPERS AND WASHERS
B3794	Cruise control function request circuit - signal incorrect	POWER POINT
B3794	Cruise control function request circuit - drive jammed	POWER POINT
B3812	Ground circuit of the sensor of the anti-theft system	anti-theft system
B3873	Front Windscreen Washer Relay Circuit	WINDSHIELD WIPERS AND WASHERS
B3875	Windshield Wiper High Speed Relay Circuit	WINDSHIELD WIPERS AND WASHERS
B3922	Front wiper function selection circuit	WINDSHIELD WIPERS AND WASHERS
B3933	Air Conditioning (A/C) Evaporator Temperature Sensor Circuit Voltage Above Threshold	HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
P0826	Upshift and Downshift Circuit - Incorrect Signal	POWER POINT
P0826	Upshift and downshift chain - drive jammed	POWER POINT
U0073	The controller communication bus is not working	DESIGN
U0100	Communication failure with ECM/PCM "A"	POWER POINT
U0101	Communication failure with TCM	POWER POINT
U0155	Communication failure with the instrument cluster controller (IPC)	DESIGN
U0164	Communication failure with body control module (BCM)	HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
U1814	High-speed powertrain communication line enable circuit	DESIGN
U2099	High-speed communication line enable circuit	DESIGN

• The body control module (BCM) detects a short to battery positive voltage in the DEFOG relay control circuit when the body control module (BCM) attempts to supply voltage to the relay.
• The body control module (BCM) detects that the DEFOG relay control circuit is open.
• The described condition must be valid for longer than 1 second.

• The body control module (BCM) stores fault code B0283 in memory.
• The glass heating will not work.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold without the fault recurring.

2. Check the positive battery voltage on the rear window heating relay coil side. Voltage is supplied to the DEFOG relay coil side via fuse EF25 (10 A).
3. Check the DEFOG relay circuit on the control side for faults that cause DTC B0283.





4. Check by ear for clicks when the DEFOG relay is triggered. Issue a command to turn on and off. Repeat the commands if necessary.
5. Check that the body control module (BCM) grounds the heated glass relay.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section "Diagnostic System Check - Vehicle" in the description of the vehicle's fault codes.
2	Replace DEFOG relay (glass heating). Connect a test lamp between the DEFOG relay power supply circuit from fuse EF25 (10 A) and the ground on the DEFOG relay socket. Turn on the ignition with the engine off. Is the indicator light on?	-	Proceed to Step 3	Proceed to Step 8
3	Turn off the ignition. Check the DEFOG relay control circuit for a short to battery positive voltage or ground. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 4
4	Connect a test lamp between the DEFOG relay power supply circuit from fuse EF25 (10 A) and the control circuit on the DEFOG relay socket. Turn on the ignition with the engine off. Using the diagnostic tool, send a command to turn the relay on and off. Does the indicator light come on and go out?	-	Proceed to Step 6	Proceed to Step 5
5	Check the DEFOG relay control circuit for an open circuit. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 7
6	Inspect the relay socket for poor contact or damaged terminals. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 9
7	Check for poor contact at the body control module (BCM) wiring harness connector. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 10
8	Eliminate short to ground, poor contact, or open circuit in the supply voltage circuit of fuse EF25 (10 A). Is the renovation completed?	-	Proceed to Step 11	-
9	Replace DEFOG relay (glass heating). Is the replacement complete?	-	Proceed to Step 11	-
10	Replace the body control module (BCM). Is the replacement complete?	-	Proceed to Step 11	-
11	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 2	The system is normal

2. At this stage, the serviceability of the winter mode switch is checked.
3. This step checks the input voltage from the BCM to the winter mode switch.
6. At this stage, the integrity of the ground circuit is checked.

Step	Operation	Values	Yes	No
1	Install the diagnostic tool. Turn on the ignition with the engine off. Turn the winter mode switch on and off while monitoring the diagnostic tool. Does the scan tool indicate ACTIVE when the switch is pressed the first time and INACTIVE when the switch is pressed a second time?	-	Jump to Section 9A, "Checking Body Wiring Systems for Intermittent Malfunctions and Contact Failures."	Proceed to Step 2
2	Disconnect the connector from the winter mode switch. Connect a jumper with a fuse to the switch signal circuit at the switch connector. Does the diagnostic tool show a change in the status of the Winter Mode parameter?	-	Proceed to Step 7	Proceed to Step 3
3	Measure the voltage in the switch signal circuit at the switch connector. Does the measured value correspond to the ignition voltage?	-	Proceed to Step 6	Proceed to Step 4
4	Measure the voltage at the body control module (BCM) switch signal circuit. Does the measured value correspond to the ignition voltage?	-	Proceed to Step 5	Proceed to Step 8
5	Check the switch signal circuit for short circuits. Has the cause been found and corrected?	-	Proceed to Step 9	Jump to Section 9A, "Checking Body Wiring Systems for Intermittent Malfunctions and Contact Failures."
6	Check the switch ground circuit for short circuits. Has the cause been found and corrected?	-	Proceed to Step 9	Jump to Section 9A, "Checking Body Wiring Systems for Intermittent Malfunctions and Contact Failures."
7	Replace the winter mode switch. Is the replacement complete?	-	Proceed to Step 9	-
8	Replace BCM. Has the cause been found and corrected?	-	Proceed to Step 9	-
9	After completing the repair, observe the "Winter mode" parameter on the diagnostic device screen, alternately turning the switch on and off. Does the scan tool indicate ACTIVE when the switch is pressed the first time and INACTIVE when the switch is pressed a second time?	-	The system is normal	Go to Step 1

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• This DTC may be stored in the DTC history without affecting the operation of the controller.
• If the fault code is only stored in the log and is not issued as a current fault code, the controller should not be replaced.
• If the DTC is received both as a current DTC and as a stored DTC, replace the controller that generated the DTC.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold without the fault recurring.

1. Program the airbag identification number into the body control module (BCM).
2. Read the trouble codes from the BCM. The DTC B1001 should change to logged.
• If the DTC remains current, replace the BCM.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold without the fault recurring.

1. Program VIN information into the body control module (BCM).
2. Turn off the ignition, wait a few seconds and turn on the ignition.
3. Read the trouble codes from the BCM. DTC B1016 should change to logged.
• If this DTC is received as current, replace the controller that set this DTC.

• The ignition switch is in the OFF or ACC position.
• The ignition switch is in the START position.

• Ignition voltage circuit 1 is shorted to supply voltage for more than 2 seconds.
• Ignition voltage circuit 1 is open for more than 2 seconds.
• Ignition voltage 1, auxiliary voltage, or off/run/start voltage circuit shorted to ground.
• There is an open or short to ground in the positive battery voltage circuit at the ignition switch.
• Open circuit in the control circuit of the relay winding "run/start" (including relay winding and ground).

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold without the fault recurring.

• A short to ground in the auxiliary wake-up serial communication circuit will cause the ignition switch fuse to blow. DTC U1814 should be current.
• A short to ground in the ignition 1 run/crank voltage circuit at the start relay will cause the ignition switch fuse to blow. DTC B1428 should be current.
• Power modes and control actions are determined by the BCM circuitry. A power mode fault is determined by comparing the displayed BCM power mode parameters in the Circuit/System Test list.

1. Inspect the ignition switch fuse for a blown fuse. The fuse should be good.
• If the fuse is blown, the following circuits should be checked for shorts to ground. If all circuits are OK, replace the BCM.
- Positive battery voltage at ignition switch Auxiliary voltage - Voltage "off/run/start" - Ignition voltage 1
2. Disconnect the ignition switch connector.
3. Check for battery positive voltage between the battery positive voltage circuit at the ignition switch and ground.
• If the voltage is below the positive battery voltage, eliminate the open or high resistance in the circuit.
4. Perform a check of the ignition switch parts.
• If the ignition switch is faulty, replace the ignition switch.
5. Turn ignition OFF, disconnect connector C1 at the BCM, test for voltage below 1.0 V between the following BCM circuits and ground.
6. Remove the ignition key, test for less than 1.0 V between the following BCM circuits and ground:
- Ignition switch resistor signal - Off/Work/Start - Auxiliary voltage Ignition voltage 1
• If the voltage is higher than 1.0 V, eliminate the short circuit to the supply voltage in the circuit.
7. Verify that the resistance in the following circuits between the BCM and the ignition switch is less than 1.0 ohms:
- Ignition switch resistor signal - Off/Work/Start - Auxiliary voltage Ignition voltage 1
• If the resistance is higher than 5 Ohms, eliminate the open circuit or increased resistance in the circuit.
8. Check for infinite resistance between the ignition switch resistor signal circuit at the BCM and ground.
• If the resistance is not infinite, eliminate the short to ground in the signal circuit.
9. Replace BCM controller.

• The ignition switch is in the START position.
• The ignition switch is in the RUN position.

• The auxiliary voltage circuit is shorted to the supply voltage for more than 2 seconds.
• The ignition auxiliary voltage circuit is open for more than 2 seconds.
• Ignition voltage 1, auxiliary voltage, or off/run/start voltage circuit shorted to ground.
• There is an open or short to ground in the positive battery voltage circuit at the ignition switch.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold without the fault recurring.

• A short to ground in the auxiliary wake-up serial communication circuit will cause the ignition switch fuse to blow. DTC U1814 should be current.
• A short to ground in the ignition 1 run/crank voltage circuit at the start relay will cause the ignition switch fuse to blow. DTC B1428 should be current.
• Power modes and control actions are determined by the BCM circuitry. A power mode fault is determined by comparing the displayed BCM power mode parameters in the Circuit/System Test list.

1. Inspect the ignition switch fuse for a blown fuse. The fuse should be good.
• If the fuse is blown, the following circuits should be checked for shorts to ground. If all circuits are OK, replace the BCM.
- Positive battery voltage at ignition switch Auxiliary voltage - Voltage "off/run/start" - Ignition voltage 1
2. Disconnect the ignition switch connector.
3. Check for battery positive voltage between the battery positive voltage circuit at the ignition switch and ground.
• If the voltage is below the positive battery voltage, eliminate the open or high resistance in the circuit.
4. Perform a check of the ignition switch parts.
• If the ignition switch is faulty, replace the ignition switch.
5. Turn ignition OFF, disconnect connector C1 at the BCM, test for voltage below 1.0 V between the following BCM circuits and ground.
6. Remove the ignition key, test for less than 1.0 V between the following BCM circuits and ground:
- Ignition switch resistor signal - Off/Work/Start - Auxiliary voltage Ignition voltage 1
• If the voltage is higher than 1.0 V, eliminate the short circuit to the supply voltage in the circuit.
7. Verify that the resistance in the following circuits between the BCM and the ignition switch is less than 1.0 ohms:
- Ignition switch resistor signal - Off/Work/Start - Auxiliary voltage Ignition voltage 1
• If the resistance is higher than 5 Ohms, eliminate the open circuit or increased resistance in the circuit.
8. Check for infinite resistance between the ignition switch resistor signal circuit at the BCM and ground.
• If the resistance is not infinite, eliminate the short to ground in the signal circuit.
9. Replace BCM controller.

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Instrument cluster light controller reference voltage	Battery voltage is above threshold	Battery voltage is above threshold	Voltage above threshold	Battery voltage is above threshold
Instrument cluster light dimmer control circuit	B3600	B3600	1	B3600
1. Interior lighting does not work

1. Clear the fault code. Disconnect the mirror control switch (dimmer).
2. Connect a multimeter between the instrument cluster dimmer reference voltage circuit and the negative battery terminal.
3. Turn on the ignition, check the voltage level 9-14 V.
• If voltage is less than 9 V, test the instrument cluster dimmer reference voltage circuit for a short to ground, open, or high resistance. If circuit and connections are normal, replace the BCM.
• If voltage is greater than 14 V, test the instrument cluster dimmer reference voltage circuit for a short to battery voltage. If circuit and connections are normal, replace BCM.
4. If the voltage is correct and all circuits and connections are good, replace the mirror control switch (dimmer).

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Mirror control switch (lighting control), replacement
• Controller information for replacing and programming BCM.

• The voltage in the system is 9 - 16 V.
• The fault code can only be generated when the output is activated.

• This fault code will only set when the output is activated and there is a short to ground in the run/start relay coil control circuit.

• The controller output driver will be disabled and the supply voltage will not be supplied to the control circuit of the "run/start" relay winding.

• The current fault code is cleared after the controller output command is removed or the fault disappears.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.
• A short to supply voltage in the control circuit of the run/start relay coil will cause the check engine light (MIL) to illuminate when the ignition switch is in the OFF position.

1. Turn off the ignition, disconnect the IGN MAIN PCB relay and connect a test lamp between the relay control circuit and ground.
2. Switch the ignition on and off alternately. The indicator lamp should light and go out when the ignition switch position changes.
• If the test lamp never illuminates, test the relay control circuit for a short to ground, open, or high resistance. If the circuit is OK, replace the BCM.
• If the test lamp remains on, test the relay control circuit for a short to battery voltage. If the circuit is OK, replace the BCM.
3. If the indicator light comes on and goes out normally, check or replace the IGN MAIN PCB relay.

• Ignition switch in ACC or RUN position.
• The car was started remotely.
• The vehicle is in RAP (Resistor Assist Power) hold mode.

• The voltage in the system is 9 - 16 V.
• The fault code can only be set when the output is activated by a command from the controller.

• This fault code will only set when the controller activates the output and there is a short to ground in the control circuit of the run relay coil.

• The controller's output driver will be disabled and no supply voltage will be supplied to this circuit.

• The current fault code is cleared after the controller output command is removed or the fault disappears.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.
• A short to supply voltage in the control circuit of the run/start relay coil will cause the check engine light (MIL) to illuminate when the ignition switch is in the OFF position.

1. With the ignition off, disconnect the RUN relay and connect a test lamp between the control circuit of the "run" relay and the positive voltage of the battery. The test lamp should not light.
• If the test lamp illuminates, test the control circuit of the run relay coil for a short to ground. If the circuits are OK and the DTC is current, replace the BCM.
2. If the circuits are OK and the DTC is "current", test or replace the RUN relay or BCM.

• The ignition switch is in the RUN position.

• The BCM detects an open or short to voltage in the off/run/crank voltage circuit when both ignition auxiliary voltage/run and ignition run/crank parameters are active.
• The BCM detects an open in the battery positive voltage circuit while the engine is running. An open in the battery voltage circuit may be caused by a short to ground in one of the following circuits:
- Positive battery voltage - Auxiliary voltage - Ignition voltage 1 - Voltage "off/run/start"

• The controller enters the emergency power mode depending on the data about the last detected effective power mode and the status of the engine run flag in the GMLAN serial communication circuits.
• The remaining controllers on the vehicle operate in a fail-safe power mode depending on the last valid power mode communicated by the BCM and the status of the engine run flag on the GMLAN serial data circuits.
• The engine cannot be started.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.

1. With the ignition off, disconnect the BCM connector.
2. With the ignition off and the key removed, or with the key in the ACC position, measure 0 V between the off/run/crank voltage circuit at the BCM connector and ground.
• If voltage is greater than 0 V, disconnect the ignition switch and test the off/run/start voltage circuit for a short to supply voltage or short to other ignition switch signal circuits.
3. With the ignition off and the key inserted, measure the battery voltage between the off/run/crank voltage circuit at the BCM connector and ground.
• If the voltage is lower than battery voltage, disconnect the ignition switch and test the off/run/start voltage circuit for an open or short to ground.
4. With the ignition switch in the RUN and START positions, measure the battery voltage between the ignition 1 voltage circuit at the BCM connector and ground.
• If the voltage is lower than battery voltage, disconnect the ignition switch and test the ignition 1 voltage circuit and the battery positive voltage circuit for an open or short to ground.
5. With the ignition switch in the ACC and RUN positions, measure the battery voltage between the accessory voltage circuit at the BCM connector and ground.
• If the voltage is lower than battery voltage, disconnect the ignition switch and test the ignition voltage circuit and the battery positive voltage circuit for an open or short to ground.

• The ignition switch is in the START position.

• The off/run/start circuit is shorted to supply voltage for more than 2 seconds.
• In the "off/run/start" circuit, the break lasts longer than 2 seconds.

• The controller enters the emergency power mode depending on the data about the last detected effective power mode and the status of the engine run flag in the GMLAN serial communication circuits.
• The remaining controllers on the vehicle operate in a fail-safe power mode depending on the last valid power mode communicated by the BCM and the status of the engine run flag on the GMLAN serial data circuits.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.

1. With the key removed from the ignition switch and in the ACC position, check for infinite resistance between the positive battery voltage terminals and the off/run/start voltage terminals at the ignition switch. Repeat the same measurement between the ignition key resistor signal terminals and the off/run/start voltage terminals at the ignition switch.
• If the resistance is not infinite, replace the ignition switch.
2. With the ignition key inserted in the OFF position, measure resistance of less than 1 ohm between the positive battery voltage terminal and the "off/run/start" voltage terminal on the ignition switch.
• If the resistance is greater than 1 ohm, replace the ignition switch.
3. With the ignition key in the RUN position, measure a resistance of less than 1 ohm between the terminals of the signal from the ignition key resistor and the "off/run/start" voltage on the ignition switch.
• If the resistance is greater than 1 ohm, replace the ignition switch.
4. With the key in the START position, measure the resistance of 1170-1430 Ohm between the terminals of the signal from the ignition key resistor and the "off/run/start" voltage on the ignition switch.
• If the measured value is outside the specified range, replace the ignition switch.

• Ignition switch in ACC or RUN position.
• The car was started remotely.
• The vehicle is in RAP (Resistor Assist Power) hold mode.

• The voltage in the system is 9 - 16 V.
• The fault code can only be generated when the output is activated by a command from the controller.

• The fault code is set only when the controller activates the output and there is a short to ground in the RAP relay control circuit.

• The controller's output driver will be disabled and no supply voltage will be supplied to this circuit.

• The current fault code is cleared after the controller output command is removed or the fault disappears.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.
• The RAP radio mode is a separate function and continues to operate normally.
• The ignition switch will not return to the OFF position if there is no voltage applied to the RAP relay.

1. Disconnect the RAP relay and connect a test lamp between the RAP relay control circuit and ground.
2. Turn on the ignition. The indicator lamp should light.
• If the test lamp does not illuminate, test the relay control circuit for a short to ground. If the circuit is OK, replace the BCM.
• If the indicator lamp comes on, check or replace the RAP relay.

• The battery voltage should be 9-16 V.

• This fault code will be cleared from the current ones once the cause of the fault has been corrected.
• The fault code in the history will be cleared after 100 consecutive ignition cycles without the fault being present.
• The history fault code and the current code can be cleared using a diagnostic tool.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition. Is DTC B1480 present?	-	Proceed to Step 3	Perform a check for intermittent faults and contact problems in connectors
3	Check the incorrectly connected power supply circuit of the entrance lighting lamps for a short to ground. Has the cause been found and corrected?	-	Proceed to Step 5	Proceed to Step 4
4	Replace the body control module (BCM). Refer to the module reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 5	-
5	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 2	The system is normal

Error code descriptions

Battery voltage is above threshold

Voltage above threshold

• Battery voltage drops below 11V, engine speed is above 1100rpm for 15 seconds.
• Battery voltage is above 16 V, engine speed is above 1100 rpm for 15 seconds.
• Battery voltage differs by 2 volts in the battery monitoring circuits of the BCM for 10 seconds.

• The fault code will lose its current status once the fault has disappeared.
• After 50 consecutive ignition cycles, if the fault condition is no longer present, the DTC is cleared from the history.
• To clear the fault code, use the "Clear fault codes" function of the diagnostic tool.

3. This step checks the voltage in the battery positive voltage monitoring circuits in the BCM. If the voltage readings are not within the specified range, the voltage monitoring circuits need to be checked.
4. This step tests the BCM ground sense circuit.
5. This step checks for proper voltage at the BCM ground sensing circuits. If the voltage is not within the proper operating range, the battery positive voltage and BCM ground circuits need to be checked.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition with the engine off. Using a scan tool, monitor the Battery Voltage parameters in the BCM data list. Do any voltages differ by more than the stated value?	2 B	Proceed to Step 5	Proceed to Step 3
3	Turn off the ignition. Disconnect the BCM wiring harness connectors. Turn on the ignition with the engine off. Measure the voltage between the BCM battery positive voltage circuits and the BCM ground circuits. Do the voltages differ by more than the specified value?	2 B	Proceed to Step 9	Proceed to Step 4
4	Measure the voltage between the battery positive voltage circuit at the BCM and a good ground. Do the voltages differ by more than the specified value?	2 B	Proceed to Step 8	Proceed to Step 7
5	Turn on the ignition. Measure the voltage between the battery positive voltage circuit and the ground circuit at the BCM. Is the measured value within the specified range?	10.5 - 15.5 V	Proceed to Step 9	Proceed to Step 6
6	Measure the voltage between the battery positive voltage circuit at the BCM and a good ground. Is the measured value within the specified range?	10.5 - 15.5 V	Proceed to Step 8	Proceed to Step 7
7	Check the battery positive voltage circuits at the BCM for high resistance or open circuits. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 9
8	Check the ground circuits at the BCM for high resistance or open circuits. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 9
9	Check the body controller wiring harness connector for poor connection. Has the cause been found and corrected?	-	Proceed to Step 11	Proceed to Step 10
10	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 11	-
11	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 2	The system is normal

• The conditions for issuing this DTC are no longer valid.
• The fault code is cleared from the history after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Front fog lamp control circuit	B2530	B2530	B2530	-

1. Turn off the ignition, disconnect the J2 connector on the instrument panel fuse block and check for a short to voltage, a short to ground, an open or increased resistance at terminal 32.
2. Turn on the ignition, activate the fog lamp output control on the scan tool and check the ground circuit at terminal 32 of the instrument panel fuse block connector.
• If ground is present, replace the engine fuse block. If ground is not present, replace the BCM.

• Replacing the Instrument Panel Fuse Box
• Controller information for BCM replacement and programming

• This fault code will be cleared from the current ones once the cause of the fault has been corrected.
• The fault code in the history will be cleared after 100 consecutive ignition cycles without the fault being present.
• DTCs in the history can be cleared using a diagnostic tool.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition with the engine off. Using the diagnostic tool, select the headlight test and issue a command to turn the reversing lights on and off. Do the reversing lights come on and go out as commanded?	-	Go to diagnostic recommendations	Proceed to Step 3
3	Check the power supply circuit of the reversing lights for a short to ground or an open circuit. Has the cause been found and corrected?	-	Proceed to Step 6	Proceed to Step 4
4	Check the power supply circuit from the CHMSL/BACKUP fuse (central stop/reverse light) to the BCM controller for a short to ground or an open circuit.	-	Proceed to Step 6	Proceed to Step 5
5	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 6	-
6	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the conditions that caused the DTC to appear. Has the DTC been cleared?	-	Proceed to Step 2	The system is normal

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Low beam headlight relay control circuit	B2575	B2575	B2575	-
Battery voltage supply circuit of the low beam relay	B2575	B2575	-	-

• The command to turn on the headlights has been given.
• The headlight dimmer must be in the low beam position.

• There is an open circuit, short circuit to ground, or short circuit to supply voltage in the low beam relay control circuit.
• There is an open circuit or short circuit to ground in the low beam relay battery supply voltage circuit.

• The conditions for issuing this DTC are no longer valid.
• The fault code is cleared from the history after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

1. Turn off the ignition, disconnect the J2 connector on the engine fuse block and check the terminal of the connector 26 for a short to voltage, a short to ground, an open or high resistance.
2. Turn on the headlight switch, set the headlight low/high beam switch to the low beam position and check the circuit at terminal 26 on connector J2 for ground.
• If ground is present, replace the engine fuse block. If ground is not present, replace the BCM.

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
The headlight switch is off	B257A	B257A	B257A	-
The parking light switch is on	B257A	B257A	B257A	-
The headlight switch is on	1	2	B2575	-
Weight of headlights	-	B257A	2	-
Headlights are constantly on - low beam or high beam Headlights not working - low beam

1. Set the headlight switch to the OFF position, disconnect the J6 connector of the BCM controller.
2. Turn on the ignition, connect a test lamp between the OFF circuit of the headlight switch and the positive terminal of the battery. Make sure that the test lamp lights.
• If the indicator lamp does not light:
Check the headlight switch OFF circuit for a short to voltage or an open.
Check the headlight ground circuit.
If the circuit/connections are OK, replace the headlight switch.
6. Set the headlight switch to the PARK position. Make sure that the indicator lamp does not light.
• If the test lamp illuminates, test the headlamp switch OFF circuit for a short to ground. If circuit/connections are OK, replace the headlamp switch.
7. Set the headlight switch to the PARK position. Connect a test lamp between the ON circuit of the parking light switch and the positive terminal of the battery. Make sure that the test lamp lights.
• If the test lamp does not illuminate, check the ON circuit of the parking lamp switch for a short to voltage or an open. If the circuit/connections are OK, replace the headlamp switch.
8. Set the headlight switch to the OFF position. Make sure that the indicator lamp does not light.
• If the test lamp illuminates, test the ON circuit of the parking lamp switch for a short to ground. If the circuit/connections are OK, replace the headlamp switch.
9. If there are no faults in the circuit or connections, replace the BCM.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Headlight Switch Replacement
• Controller information for BCM replacement and programming

• When the BCM is commanded to turn the high beams OFF and the high beam relay control circuit is shorted to ground.
• When the BCM is commanded to turn the high beam headlamps ON and the high beam relay control circuit is shorted to voltage or open.

• This fault code will be cleared from the current ones once the cause of the fault has been corrected.
• The fault code in the history will be cleared after 100 consecutive ignition cycles without the fault being present.
• The history fault code and the current code can be cleared using a diagnostic tool.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition with the engine off. Using the diagnostic tool, send a command to turn the high beam relay on and off. Does the high beam relay turn on and off according to the commands received?	-	Perform a check for intermittent faults and contact problems in connectors	Proceed to Step 3
3	Turn off the ignition. Disconnect the high beam relay. Turn on the ignition with the engine off. Check the high beam relay positive voltage circuit with a test lamp connected to a good ground. Is the indicator light on?	-	Proceed to Step 4	Proceed to Step 10
4	Connect a test lamp between the high beam relay control circuit and the high beam relay battery positive circuit. Using the diagnostic tool, issue a command to turn the high beam relay on and off. Does the indicator light come on and go out according to each command?	-	Proceed to Step 8	Proceed to Step 5
5	Does the control lamp continue to light with any command?	-	Proceed to Step 7	Proceed to Step 6
6	Check the high beam relay control circuit for a short to battery positive or an open. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 9
7	Check the high beam relay control circuit for a short to ground. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 9
8	Check the high beam relay in the engine fuse box for increased resistance or poor contact. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 12
9	Check for high resistance or poor connection at the body control module (BCM) harness connector. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 13
10	Check the wiring harness connectors at the engine fuse box for increased resistance or poor connections. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 11
11	Replace the engine fuse box. Is the renovation completed?	-	Proceed to Step 14	-
12	Replace the high beam relay in the engine fuse box. Is the renovation completed?	-	Proceed to Step 14	-
13	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 14	-
14	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 2	The system is normal

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Parking Light Relay Control	B2585	B2585	B2585	-

• The conditions for issuing this DTC are no longer valid.
• The fault code is cleared from the history after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

1. Turn off the ignition, disconnect the J2 connector on the engine fuse block and check terminal 33 of the connector for a short to supply voltage, a short to ground, an open or increased resistance.
2. Using a diagnostic tool, activate the parking light output control and check the ground at terminal 33 of connector J2 on the engine fuse block.
• If ground is present, replace the engine fuse block. If ground is not present, replace the BCM.

• Engine fuse box replacement
• Controller information for BCM replacement and programming

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Power supply for LED indicator dimmer	B2625	B2625	B2625	-

• The conditions for issuing this DTC are no longer valid.
• The fault code is cleared from the history after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

1. Turn ignition off, turn parking lights off, disconnect all LED components in the dimmer supply circuit. Verify that DTC B2625 is not set.
• If the fault code is restored, check the supply voltage circuit of the LED indicator light controller for a supply voltage fault, ground fault, or open circuit. If the circuit/connections are in order, replace the BCM controller, the driver's door switch, and the passenger's door switch, respectively.
2. Connect the elements one by one and check for the B2625 fault code.
• If the fault code is restored, replace the corresponding element.
• If the DTC is not set, replace the BCM.

• Refer to the appropriate replacement procedure for the component causing the malfunction.
• Controller information for replacement, setup and programming of BCM

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Ambient Light Sensor Signal Circuit	B2645 Ambient Light Sensor Circuit Above Threshold	B2645 Ambient Light Sensor Circuit Below Threshold	B2645 Ambient Light Sensor Circuit Above Threshold	B2645 Ambient Light Sensor Circuit Below Threshold or B2645 Ambient Light Sensor Circuit Above Threshold
Outside Light Sensor Ground Circuit	-	B2645 Ambient Light Sensor Circuit Below Threshold	-	B2645 Ambient Light Sensor Circuit Below Threshold or B2645 Ambient Light Sensor Circuit Above Threshold

• The cause of this fault code has been corrected.
• A command to clear fault codes was issued using the diagnostic tool.
• The fault code in the history is cleared after 100 consecutive ignition cycles without a fault.

1. Turn off the ignition, disconnect the outside light sensor.
2. Turn ignition on, observe the "Ambient Light Sensor" parameter in the BCM data list on the scan tool.
• If the parameter on the scan tool shows less than 7 V, find and fix an open, high resistance, or short to ground in the ambient light sensor signal circuit, or replace the ambient light sensor.
• If the parameter on the diagnostic tool shows more than 10.5 V, you should find and eliminate the short to supply voltage in the signal circuit of the outside light sensor.
3. If the circuits are OK, replace the BCM.

• Replacing the ambient light sensor
• Controller information for BCM replacement and programming

1. The ignition switch is in the ON position.
2. The brake pedal is pressed.
3. The gearbox is in the PARK position.

• Current DTC B2705 will be cleared when the fault is cleared and the ignition is cycled.
• All BCM history DTCs will clear after 100 ignition cycles without issuing any current DTCs for 100 ignition cycles.

1. Using a scan tool, verify that there are no DTCs associated with the brake pedal position sensor and/or transmission internal mode switch (IMS) that could prevent the BCM from supplying battery voltage to the BTSI solenoid.
2. If the automatic transmission shift lock control circuit is shorted to battery positive voltage, the BTSI solenoid will not operate. On vehicles with a floor mounted shift lever, shifting from PARK will be accomplished without pressing the brake pedal. On vehicles with a steering column mounted shift lever, the shift lever must be locked in PARK.
3. Perform tests by wiggling the wires and connectors. Intermittent faults can often be detected this way.

2. Listen for the click when the BTSI solenoid is activated. Issue a command to turn it on and off. Repeat the commands if necessary.
3. This step checks the battery voltage in the BTSI solenoid control circuit.
4. At this stage the BTSI solenoid control circuit is checked for an open or short to ground.
5. At this stage, the BTSI solenoid ground circuit is checked for an open circuit.

Step	Operation	Values	Yes	No
1	Install the diagnostic tool. Turn on the ignition with the engine off. Using the diagnostic tool, command the lock solenoid to turn on and off. Using a scan tool, check the BTSI solenoid control parameter in the body control module (BCM) data list. Does the BTSI solenoid turn on and off as commanded?	-	Perform a check in case of intermittent malfunction and contact problems in connectors.	Proceed to Step 2
2	Turn off the ignition. Disconnect the BTSI solenoid. Connect a test light between the BTSI solenoid control circuit at the BTSI solenoid connector and a good ground. Turn on the ignition with the engine off. Using the diagnostic tool, command the BTSI solenoid to turn on and off several times. Does the indicator light come on and go out as commanded?	-	Proceed to Step 4	Proceed to Step 3
3	Check the BTSI solenoid control circuit for an open or short to ground. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
4	Check the BTSI solenoid ground circuit for an open. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 5
5	Inspect the wiring harness connector at the BTSI solenoid for poor connections. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 7
6	Check the body controller wiring harness connector for poor connection. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 8
7	Replace BTSI solenoid. Is the replacement complete?	-	Proceed to Step 9	-
8	Important: Perform BCM setup procedures. Replace BCM controller. Is the replacement complete?	-	Proceed to Step 9	-
9	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Go to Step 1	The system is normal

• The EBCM disables the ABS-TCS/ESP systems during the ignition cycle.
• One or more of the following warning indicators may be on:
• ABS-TCS warning indicator,
• ABS-TCS warning indicator,
• ESP warning indicator,
• Brake Malfunction Indicator and/or
• Warning indication of departure from course.

2. Confirmation that the fault that caused this DTC to be issued is currently present.
3. Confirms the integrity of the internal circuits of the ECBM controller. An internal fault within the ECBM controller may cause this DTC to be generated.

Step	Operation	Values	Yes	No
1	Is the diagnostic system check complete?	-	Proceed to Step 2	Proceed to the diagnostic circuit check in this section.
2	Turn off the ignition for 10 seconds. Operate the vehicle in the conditions that caused the installation of this DTC, or perform road tests at speeds greater than 15 km/h. View DTCs using a scan tool. Is DTC C0131 (B2745) set on this ignition cycle?	-	Proceed to Step 3	Proceed to Step 4
3	Are fault codes C0550 or C0551 also set?	-	Refer to DTCs C0550 and C0551 in this section.	Proceed to Step 4
4	Test all EBCM ground circuits for high resistance or open circuits. Check ABS-TCS/ESP fuses and replace if necessary. Test the EBCM battery supply voltage circuit for high resistance, open, or short to ground. Has any cause for the malfunction been found and corrected?	-	Proceed to Step 7	Proceed to Step 5
5	Check the EBCM wiring connector for poor connections. Has any cause for the malfunction been found and corrected?	-	Proceed to Step 7	Proceed to Step 6
6	Replace the hydraulic modulator. See "Brake Modulator Assembly" in this section. Is the renovation finished?	-	Proceed to Step 7	-
7	Clear DTCs using a diagnostic tool. Turn off the ignition for 10 seconds. Test the vehicle under the conditions that caused DTC C0131 (B2745) to set. Is DTC C0131 (B2745) set on this ignition cycle?	-	Proceed to Step 2	Proceed to Step 8
8	On the diagnostic tool, select the function for displaying fault codes. Does the scan tool show any trouble codes?	-	Go to the table of the corresponding fault code.	The system is normal

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Horn Relay Control	1	2	B2750	-
Sound signal control	2	2	2	-
Sound signal mass	-	2	-	-
Horn switch weight	-	2	-	-
The sound signal devices operate continuously The sound signal devices do not work

• The fault code is cleared after the fault disappears.
• The current fault code will be transferred to the log when the exit request is removed.
• The fault code in the history will be cleared after 50 consecutive ignition cycles without a fault.

1. Turn off ignition, disconnect harness connector J2 at engine fuse block.
2. Connect a test lamp between the control circuit at terminal 22 and the battery voltage.
3. Using the diagnostic tool, issue commands to turn the horn on and off. The indicator lamp should light and go out in accordance with the commands.
• If the test lamp is constantly on, check the control circuit for a short to ground. If the circuit is OK, replace the body controller.
• If the test lamp is always off, check the control circuit for a short to supply voltage or an open/high resistance. If the circuit is OK, replace the body controller.
4. If all circuits are good, check or replace the engine fuse box.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Replacing the junction block
• Controller information for replacing and programming the body controller

• The voltage in the system should be 9-16 V.
• The anti-theft system is in a state of readiness.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Turn off the ignition. Disconnect the tilt sensor harness connector. Check the battery positive voltage circuit at the tilt sensor harness connector with a test light connected to a good ground. Is the indicator light on?	-	Proceed to Step 3	Proceed to Step 7
3	Using a digital multimeter, measure the voltage in the tilt sensor signal circuit at the tilt sensor harness connector. Is the measured voltage equal to the battery voltage?	9 - 16 V	Proceed to Step 4	Proceed to Step 5
4	Check the tilt sensor power circuit for a short to battery voltage, short to ground, or open. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
5	Check the tilt sensor signal circuit for an open or short to ground. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
6	Check the tilt sensor harness connector for poor connection or poor contact. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 8
7	Repair the positive battery voltage supply circuit to the tilt sensor. Has the cause been eliminated?	-	Proceed to Step 9	-
8	Replace the tilt sensor. Has the cause been eliminated?	-	Proceed to Step 9	-
9	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 10	The system is normal
10	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	The system is normal	-

• The voltage in the system should be 9-16 V.
• The anti-theft system is in a state of readiness.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Turn off the ignition. Disconnect the intrusion sensor wiring harness connector. Test the battery positive voltage circuit at the intrusion sensor harness connector with a test light connected to a good ground. Is the indicator light on?	-	Proceed to Step 3	Proceed to Step 7
3	Using a digital multimeter, measure the voltage in the intrusion sensor signal circuit at the intrusion sensor harness connector. Is the measured voltage equal to the battery voltage?	9 - 16 V	Proceed to Step 4	Proceed to Step 5
4	Check the intrusion sensor power circuit for a short to battery voltage, short to ground, or open. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
5	Check the faulty tilt sensor signal circuit for an open or short to ground. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
6	Check the intrusion sensor wiring harness connector for poor connection or poor contact. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 8
7	Repair the circuit supplying positive battery voltage to the intrusion sensor. Has the cause been eliminated?	-	Proceed to Step 9	-
8	Replace the intrusion sensor. Is the replacement complete?	-	Proceed to Step 9	-
9	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 10	The system is normal
10	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	The system is normal	-

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Passenger Door Release Relay Control	B3130	1	1	-
Electric door locks not working - all doors

1. Disconnect the J2 connector on the instrument panel fuse box. Check if the fault code is reset.
• If the fault code does not reset, replace the instrument panel fuse box.
2. Check the door power relay control circuit for a short circuit to the supply voltage.
• If all circuits and connections are normal, replace the BCM.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Controller information for replacement, setup and programming of BCM
• Replacing the Instrument Panel Fuse Box

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Door lock relay control	B3135	1	1	-
Electric door locks not working - all doors

1. Disconnect the lock relay in the instrument panel fuse box. Check if the fault code is reset.
• If the fault code is not displayed, replace the relay.
2. Disconnect the J2 connector on the instrument panel fuse box. Check if the fault code is reset.
• If the fault code does not reset, replace the instrument panel fuse box.
3. Check the door lock relay control circuit for a short to ground.
• If all circuits and connections are normal, replace the BCM.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Controller information for replacement, setup and programming of BCM
• Replacing the Instrument Panel Fuse Box

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Lift glass release switch signal	1	1	1	-
Lift glass latch release signal	B3265	1	1	-
Control of the lifting glass release drive	1	1	1	-
Glass lift release switch mass	-	1	-	-
Weight of the lifting glass release drive	-	1	-	-
The release of the lifting glass latch does not work

• The voltage in the system should be 9-18 V.
• An attempt is made to unlock the lifting glass.

• The fault code has a current status only as long as the command to unlock the lifting window is in effect.
• The fault code in the history will be cleared after 50 ignition cycles without a fault.

1. Disconnect the J3 connector of the BCM controller.
2. Verify that the test lamp does not illuminate when connected between the battery voltage circuit and the window latch release signal circuit terminal on the harness connector.
• If the test lamp illuminates, test the signal circuit for a short to ground. If the circuits are OK, replace the rear wiper motor controller.
3. If the lift glass latch release signal circuit is normal, replace the BCM.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Brake light supply voltage	B3445	B3445	B3445	-

• The conditions for issuing this DTC are no longer valid.
• The fault code is cleared from the history after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

1. Disconnect the brake lights and check each brake light assembly individually for internal shorts between all terminals.
• If short circuits are detected between the terminals, replace the brake light socket or board, respectively.
2. Check the brake light power supply circuit for a short to voltage, short to ground, open, or high resistance.
• If all circuits and connections are normal, replace the BCM.

• Replacing the tail light bulb
• Controller information for BCM replacement and programming

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

• The condition that set the DTC has been corrected and the DTC has been cleared using the scan tool.
• The BCM automatically clears the history DTC if the current DTC is not detected for 100 consecutive ignition cycles.

• This DTC can only set when the output is activated by a command from the BCM.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to the section Diagnostic check of the vehicle system
2	Turn off the ignition. Disconnect the intrusion sensor wiring harness connector. Disconnect the BCM wiring harness connector. Check the rain sensor auxiliary voltage circuit for a short to ground or an open. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 3
3	Check the ground circuit of the rain sensor for an open or short to supply voltage. Has the cause been found and corrected?	9 - 16 V	Proceed to Step 7	Proceed to Step 4
4	Check rain sensor signal circuit 2 for an open or short to ground or a short to supply voltage. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 5
5	Check the rain sensor wiring harness connector for poor connection or poor contact. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 6
6	Replace the rain sensor. Has the cause been eliminated?	-	Proceed to Step 7	-
7	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 8	The system is normal
8	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	The system is normal	-

• This DTC can only set when the output is activated by a command from the BCM.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to the section Diagnostic check of the vehicle system
2	Turn off the ignition. Disconnect the intrusion sensor wiring harness connector. Disconnect the BCM wiring harness connector. Check the rain sensor auxiliary voltage circuit for a short to ground or an open. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 3
3	Check the ground circuit of the rain sensor for an open or short to supply voltage. Has the cause been found and corrected?	9 - 16 V	Proceed to Step 7	Proceed to Step 4
4	Check rain sensor signal circuit 1 for an open or short to ground or a short to supply voltage. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 5
5	Check the rain sensor wiring harness connector for poor connection or poor contact. Has the cause been found and corrected?	-	Proceed to Step 7	Proceed to Step 6
6	Replace the rain sensor. Is the replacement complete?	-	Proceed to Step 7	-
7	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 8	The system is normal
8	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	The system is normal	-

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Windshield Washer Switch Signal	6	8	1	-
Windshield wiper motor relay coil supply voltage	B3715	2	6	-
Windshield wiper high speed switch signal	6	4	1	-
Windshield wiper low speed switch signal	B3922	3	1	-
Windshield wiper motor parking switch signal	5	5	-	-
Windshield wiper motor high speed control	2	4	-	-
Windshield wiper motor low speed control	2	3	-	-
Windscreen wiper motor weight	-	2	-	-
Windscreen wiper switch weight	-	1	-	-
High Speed Wiper Relay Control	7	4	B3875	-
Windscreen wiper relay mass	-	2	-	-
Windscreen wipers and washers do not work in any mode. The windshield wipers do not work in any mode, but the windshield washers work. Windscreen wipers do not work with delay or low speed. High speed windshield wipers do not work. The windshield wiper parking does not work. The windshield wipers are constantly running. Windscreen wipers operate at high speed in low speed mode. Windshield washer malfunction.

• The current DTC is moved to the history when the exit command is cancelled or the cause of the DTC is corrected.
• The fault code in the history will be cleared after 50 consecutive ignition cycles without the fault being present.

1. Turn off ignition, disconnect harness connector J2 at engine fuse block.
2. Connect a test lamp between the control circuit at terminal 25 and ground.
3. Using the diagnostic tool, issue commands to turn the windshield wiper relay on and off. The indicator lamp should light and go out in accordance with the commands.
• If the test lamp is constantly on, check the control circuit for a short to supply voltage. If the circuits are OK, check or replace the body controller.
• If the test lamp never illuminates, test the control circuit for a short to ground, open, or high resistance. If the circuits are OK, test or replace the body control module.
4. If all circuits are good, check or replace the engine fuse box.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Engine fuse box replacement
• Controller information for BCM replacement and programming

Error code descriptions

Wrong signal

The drive is jammed

• The speed stabilizer switch is set to the on position.
• The ignition switch is set to the ON position.

• The BCM detects an abnormal voltage signal in the cruise control system "+ RES" and "- SET" switch signal circuits.
• The described condition is valid for 0.5 seconds.

• The BCM stores the DTC information in memory if the diagnostic run ends with a fault detected.
• The Malfunction Indicator Lamp (MIL) does not illuminate.
• The cruise control system is disabled.

• The fault code is transferred to the log after the fault is corrected.
• The fault code in the log is cleared after 100 ignition cycles without a fault.
• The BCM receives a command to clear the code from the scan tool.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition with the engine off. Using a diagnostic tool, monitor the Cruise Control Switch parameter. Does the "Cruise Control Switch" parameter show an error?	-	Proceed to Step 3	Proceed to Step 4
3	Turn off the ignition. Disconnect the Multi-ASM switch. Turn on the ignition with the engine off. Using a diagnostic tool, monitor the Cruise Control Switch parameter. Does the "Cruise Control Switch" parameter show an error?	-	Proceed to Step 9	Proceed to Step 11
4	Set the speed stabilizer switch to the on position. Using a diagnostic tool, monitor the Cruise Control Switch parameter. Does the "Cruise Control Switch" parameter show an error?	-	Proceed to Step 7	Proceed to Step 5
5	Press the "SET/COAST" switch of the automatic cruise control system. Using the diagnostic tool, observe the parameter "Cruise control switch". Does the "Cruise Control Switch" parameter show an error?	-	Proceed to Step 7	Proceed to Step 6
6	Press the switch "RESUME/ACCEL" automatic cruise control systems. Using the diagnostic tool, observe the parameter "Cruise control switch". Does the "Cruise Control Switch" parameter show an error?	-	Proceed to Step 7	Go to diagnostic recommendations
7	Important: The cruise control switch must be in the ON position for the multimeter to correctly display the resistance value of the "SET/COAST" switch. Turn off the ignition. Using a multimeter, measure the resistance at the cruise control switch between the "ignition 1" voltage circuit and the "SET/COAST" switch signal circuit and "RESUME/ACCELERATE". Press and hold the switches of the automatic speed control system functions separately, while simultaneously measuring the resistance values of each switch of the automatic speed control system functions. Are the measured resistance values of the cruise control function switch within the specified value ranges?	Off = circuit break On = 7.8 kOhm - 8.6 kOhm Resume = 2.7 kOhm - 3.0 kOhm Set = 1.2 kOhm - 1.3 kOhm	Proceed to Step 8	Proceed to Step 11
8	Check the "ignition 1" voltage circuit for increased resistance. Has the cause been found and corrected?	-	Proceed to Step 15	Proceed to Step 10
9	Check the signal circuits of the "SET/COAST" switch and "RESUME/ACCELERATE" automatic cruise control systems for short circuits to supply voltage. Has the cause been found and corrected?	-	Proceed to Step 15	Proceed to Step 2
10	Check the signal circuits of the "SET/COAST" switch and "RESUME/ACCELERATE" automatic cruise control systems for increased resistance. Is the renovation completed?	-	Proceed to Step 15	Proceed to Step 12
11	Inspect the Multi-ASM switch for poor contact. Has the cause been found and corrected?	-	Proceed to Step 15	Proceed to Step 13
12	Check the body controller wiring harness connector for poor connection. Has the cause been found and corrected?	-	Proceed to Step 15	-
13	Replace the cruise control switch. Is the replacement complete?	-	Proceed to Step 15	-
14	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 15	-
15	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the conditions that caused the DTC to appear. Has the DTC been cleared?	-	Go to Step 2	The system is normal

• The voltage in the system should be 9-16 V.
• The anti-theft system is in a state of readiness.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Check the intrusion sensor wiring harness connector for poor connection or poor contact. Has the cause been found and corrected?	-	Proceed to Step 6	Proceed to Step 3
3	Check the body controller wiring harness connector for poor connection or contact failure. Has the cause been found and corrected?	9 - 16 V	Proceed to Step 6	Proceed to Step 4
4	Turn off the ignition. Disconnect the intrusion sensor wiring harness connector. Disconnect the BCM wiring harness connector. Check the ground circuit of the intrusion sensor for an open. Has the cause been found and corrected?	-	Proceed to Step 6	Proceed to Step 5
5	Replace the intrusion sensor. Is the replacement complete?	-	Proceed to Step 6	-
6	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the DTC occurrence conditions specified in the accompanying text. Has the DTC been cleared?	-	Proceed to Step 7	The system is normal
7	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	The system is normal	-

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Windshield Washer Switch Signal	2	1	3	-
Windshield Washer Pump Control	1	1	2	-
Windshield Washer Relay Control	2	1	B3873	-
Windshield washer pump weight	-	1	-	-
Windscreen wiper switch weight	-	3	-	-
The washer does not work The washers are on all the time Windshield wiper system malfunction

• The current DTC is moved to the history when the exit command is cancelled or the cause of the DTC is corrected.
• The fault code in the history will be cleared after 50 consecutive ignition cycles without the fault being present.

1. Turn off the ignition, disconnect the J2 harness connector at the instrument panel fuse block.
2. Connect a test lamp between the control circuit at terminal 43 and the battery voltage.
3. Using the diagnostic tool, issue commands to turn the windshield wiper/washer motor on and off. The indicator lamp should light and go out in accordance with the commands.
• If the test lamp is constantly on, check the control circuit for a short to ground. If the circuit is OK, replace the body controller.
• If the test lamp is always off, check the control circuit for a short to supply voltage or an open/high resistance. If the circuit is OK, replace the body controller.

5. If all circuits are good, check or replace the engine fuse box.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Replacing the junction block
• Controller information for BCM replacement and programming

Important: Before performing a diagnostic procedure, it is always necessary to diagnostic check of the vehicle system.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Windshield Washer Switch Signal	6	8	1	-
Windshield wiper motor relay coil supply voltage	B3715	2	6	-
Windshield wiper high speed switch signal	6	4	1	-
Windshield wiper low speed switch signal	B3922	3	1	-
Windshield wiper motor parking switch signal	5	5	-	-
Windshield wiper motor high speed control	2	4	-	-
Windshield wiper motor low speed control	2	3	-	-
Windscreen wiper motor weight	-	2	-	-
Windscreen wiper switch weight	-	1	-	-
High Speed Wiper Relay Control	7	4	B3875	-
Windscreen wiper relay mass	-	2	-	-
Windscreen wipers and washers do not work in all modes Windscreen wipers do not work in all modes, washers work Windscreen wipers do not work in delay or low speed mode Windscreen wipers do not work at high speed Windscreen wipers do not reset to their original position Windscreen wipers are on all the time Windscreen wipers operate at high speed in low speed mode Washer malfunction

• The current DTC is moved to the history when the exit command is cancelled or the cause of the DTC is corrected.
• The fault code in the history will be cleared after 50 consecutive ignition cycles without the fault being present.

1. Turn off ignition, disconnect harness connector J2 at engine fuse block.
2. Connect a test lamp between the control circuit at terminal 21 and the battery voltage.
3. Using the diagnostic tool, issue commands to turn the high-speed windshield wiper relay on and off. The indicator lamp should light and go out according to the commands.
• If the test lamp is always on, test the control circuit for a short to ground. If the circuits are OK, test or replace the body control module.
• If the test lamp is always off, test the control circuit for a short to voltage or an open/high resistance. If the circuits are OK, test or replace the body control module.
4. If all circuits are good, check or replace the engine fuse box.

Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.

• Engine fuse box replacement
• Controller information for BCM replacement and programming

• The ignition switch is set to the ON position.
• The ignition voltage is between 9 and 16 V.

• The BCM does not activate the low speed output.
• The windshield wipers will only operate at high speed.

• This DTC will clear once the cause of the malfunction has been corrected.
• A history DTC will clear after 50 consecutive ignition cycles in which the fault does not occur.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Set the ignition switch to the ON position. Turn the windshield wiper switch to all positions. Are your windshield wipers working properly?	-	Perform a check for intermittent faults and contact problems in connectors	Proceed to Step 3
3	Set the ignition switch to the OFF position. Disconnect the windshield wiper switch connector. Using the diagnostic tool, observe the "Windshield wiper switch" parameter. Turn on the ignition with the engine off. Does the Windshield Wiper Switch parameter show OFF?	-	Proceed to Step 5	Proceed to Step 4
4	Check the low speed wiper switch signal circuit for the following faults: Short circuit to ground Short circuit to battery voltage Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 6
5	Inspect the wiring harness connector at the windshield wiper/washer switch for poor connections. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 7
6	Check for poor contact at the body control module (BCM) wiring harness connector. Has the cause been found and corrected?	-	Proceed to Step 9	Proceed to Step 8
7	Replace the windshield wiper switch. See "Replacing the multifunction turn signal switch". Is the replacement complete?	-	Proceed to Step 9	-
8	Replace the BCM. Refer to the controller reference material for replacement and programming procedures. Is the replacement complete?	-	Proceed to Step 9	-
9	Clear DTCs using a scan tool. Has the DTC been cleared?	-	Go to Step 2	The system is normal

• The ignition is on.

• Segment lights up on HVAC controller "A/C OFF" ("the air conditioner is turned off").
• The air conditioning compressor switches off.

• The fault code will be transferred to the log if the HVAC controller no longer detects a fault.
• The fault code in the history will be cleared after 50 ignition cycles without a fault.
• The fault code can be cleared using a diagnostic tool.

3. At this stage, the correct operation of the circuit in the upper voltage range is checked.
4. This step checks for proper operation of the circuit in the lower voltage range. If the fuse on the jumper blows during this test, there is a short to supply voltage in the signal circuit.

Step	Operation	Values	Yes	No
1	Has the vehicle system diagnostic check been completed?	-	Proceed to Step 2	Go to section Diagnostic check of the vehicle system
2	Install the diagnostic tool. Turn on the ignition with the engine off. Using a diagnostic tool, monitor the Evaporator Temp parameter. Does the scan tool indicate that the Evaporator Temperature parameter is within the specified range?	0.09 - 4.90 V	Proceed to Step 3	Proceed to Step 4
3	Check the connection on the climate control panel and replace the terminals if necessary. Is the renovation finished?	-	The system is normal	Proceed to Step 4
4	Turn off the ignition. Disconnect the evaporator temperature sensor. Turn on the ignition with the engine off. Using a diagnostic tool, monitor the Evaporator Temp parameter. Is the "Evaporator Temperature" parameter higher than the specified value?	4.09 V	Proceed to Step 5	Proceed to Step 6
5	Turn off the ignition. Connect a jumper wire with a 3-amp fuse between the evaporator temperature sensor signal circuit and the evaporator temperature sensor low reference circuit. Turn on the ignition with the engine off. Using a diagnostic tool, monitor the Evaporator Temp parameter. Is the "Evaporator Temperature" parameter below the specified value?	0.09 V	Proceed to Step 10	Proceed to Step 7
6	Check the evaporator temperature sensor signal circuit for a short to ground. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 11
7	Check the evaporator temperature sensor signal circuit for one of the following faults: Short circuit to supply voltage High resistance Cliff Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 8
8	Test the evaporator temperature sensor low reference circuit for one of the following conditions: High resistance Cliff Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 9
9	Check the following signal circuits for shorts to supply voltage: Cabin air temperature sensor Outside air temperature sensor Left sun sensor Right sun sensor Outdoor light sensor Has the cause been found and corrected? Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 11
10	Inspect the evaporator temperature sensor wiring harness connector for poor connections. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 12
11	Check the wiring harness connector on the heating, ventilation and air conditioning (HVAC) controller for any contact issues. Has the cause been found and corrected?	-	Proceed to Step 14	Proceed to Step 13
12	Replace the evaporator temperature sensor. See Section 7B, Manual Controls for Heating, Ventilating, and Air Conditioning Systems. Has the cause been found and corrected?	-	Proceed to Step 14	-
13	Replace the HVAC controller. For replacement, setup, and programming procedures, see section 7B, "Manual Control of the Heating, Ventilation, and Air Conditioning System". Is the replacement complete?	-	Proceed to Step 14	-
14	Use a diagnostic tool to clear the DTCs. Operate the vehicle under the conditions that caused the DTC to appear. Has the DTC been cleared?	-	Go to Step 2	The system is normal

• Wiring harness between up/down shift switch and BCM
• Up/Down Shift Switch
• BCM

Gear shift lever position	Output pin (6)
D	-0.3... 0.3 V
m	0.68... 0.78 V
M+	2.18... 2.55 V
M-	1.11... 1.30 V

Step	Operation	Values	Yes	No
1	Set the ignition switch to the OFF position. Connect the diagnostic tool. With the engine off, set the ignition switch to the ON position. Select the "Save Status/Failure Records" item in the "Diagnostic Code Information" menu Save status records/fault logs. Select "Clear DTC Information" from the "Diagnostic Trouble Code Information" menu. Clear fault code information. Drive the vehicle for one cycle. Does the winter mode lamp flash?	-	Proceed to Step 2	Eliminate temporary contact failure in the connector.
2	Select "Request DTCs by Status" from the "Diagnostic Trouble Code Information" menu. Request fault codes by status. Is DTC P0826 shown?	-	Proceed to Step 3	Eliminate temporary contact failure in the connector.
3	Check the 12V reference circuit for a short to ground or an open between the up/down switch and the BCM. Was a fault found?	-	Eliminate short to ground or open circuit.	Proceed to Step 4
4	Check the signal circuit for an open, short to voltage, short to ground between the up/down shift switch and the BCM. Was a fault found?	-	Eliminate open circuit, short circuit to supply voltage or short circuit to ground in the signal circuit.	Proceed to Step 5
5	Inspect the circuit for an open, short to supply voltage, or short to ground between the upshift/downshift switch and ground. Is there a problem found?	-	Eliminate the open circuit, short circuit to supply voltage or short circuit to ground in the circuit.	Proceed to Step 6
6	With the ignition on, check the voltage at the output terminal of the upshift/downshift switch by moving the gearshift lever. See diagnostic recommendations. Does the measured value match the specified value?	-	Replace BCM controller.	Replace the gear shift lever assembly.

• The supply voltage of the controllers is within the normal operating range.
• The vehicle's power mode requires data exchange via a serial communication line.

• The controller stops transmitting all commands.
• The controller uses standard values for all parameters received via serial communication lines.
• The controller prohibits the setting of all other fault codes.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• An intermittent fault may be caused by a short in the high speed GMLAN communication lines.
• This DTC cannot be retrieved with the status current. The diagnostic symptom "Screen scan tool not communicating with device on high speed GMLAN" is being diagnosed.
• Specific controllers that use the high speed GMLAN communication line are listed in the Communication Lines List.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Low Speed Serial Communication Line GMLAN	1	U0140 - U0214	1	-
Battery Positive Voltage Circuits	U0100 - U0214	U0100 - U0214	-	-
Ignition Voltage Circuits	U0100 - U0214	U0100 - U0214	-	-
Controller ground circuits	-	U0100 - U0214	-	-
Auxiliary wake-up circuit of serial communication line	U1814	U0100, U0101	-	-
Enabling the serial communication line	U2099	U0121	-	-
The scan tool does not communicate with a device on the high speed GMLAN network

• The voltage in the system is 9 - 16 V.
• The vehicle power mode master device requires serial data exchange to operate.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• Using the above list of fault code definitions, determine which controller is experiencing communication problems.
• If communication with multiple controllers is lost, select the one closest to the Data Link Connector (DLC).
• Information on whether a particular controller uses the high-speed or low-speed GMLAN communication channel is provided in the Communication Channel Reference section.
• Some controllers do not have internal protection for certain voltage outputs and may cause the battery positive voltage fuse or ignition voltage supply to blow. If the input voltage fuse is blown but no short circuit is detected in that circuit, make sure there are no shorted to ground voltage output circuits on the controllers before replacing the controller.
• This diagnostic can be used on any module that is required to communicate over the high or low speed GMLAN serial data line, provided the vehicle is equipped with an option that uses that module.

1. Use the above list of fault code definitions and diagnostic recommendations to determine which controller with the communication problem needs to be tested.
2. Turn off the ignition, disconnect the wiring harness connector on the controller where the connection is broken.

Important: Only high speed GMLAN controllers have a serial communications enable circuit OR an auxiliary serial communications wake-up circuit. Refer to the controller schematics to determine which controllers have these circuits. If the controller with the communication problem is missing one of these circuits, go to step 4.

3. Turn ignition ON, verify that the test lamp illuminates between the serial data line enable circuit OR the auxiliary serial data line wake-up circuit and ground.
• If the test lamp does not light, repair the open or high resistance in the circuit. If there are no faults in the circuits, replace the BCM.
4. Turn on the ignition, check if the test lamp lights between all positive battery voltage circuits and ground.
• If the test lamp does not light, eliminate the short to ground or open/high resistance in the circuit. If the circuit fuse is blown, also check the positive voltage outputs on the controller for a short to ground. If the circuits are OK, replace the faulty controller.
5. Check if the test lamp lights between all ignition voltage circuits and ground.
• If the test lamp does not light, eliminate the short to ground or open/high resistance in the circuit. If the circuit fuse is blown, also check the positive voltage outputs on the controller for a short to ground. If the circuits are OK, replace the faulty controller.
6. Check that the resistance between the controller ground circuits and the ground is no higher than 1 Ohm.
• If it is higher than 1 Ohm, repair the open circuit in the ground circuit.
7. Using the communication line list, determine if the controller with the communication problem is using a low speed GMLAN serial communication line.
• If the controller uses only high speed GMLAN communication line, replace the controller.
8. Verify that the resistance in the low speed GMLAN serial data line between the controller with the communication problem and the controller setting the fault code is less than 1 ohm.
• If the resistance is greater than 1 ohm, test the low speed GMLAN serial data circuit for an open or high resistance.
9. If all circuits are OK, replace the controller with communication problems.

• Information on replacing, configuring and programming controllers is provided in the "Controller Information" section
• GMLAN Wiring Replacement

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Auxiliary wake-up circuit of serial communication line	U1814	U0100	-	-

• The voltage in the system is 9 - 16 V.
• The vehicle power mode master device requires serial data exchange to operate.

• Controllers use the default values of missing parameters until the next ignition cycle.
• The controllers never issued signals, so certain subsystems will not work.
• The engine cannot be started.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.
• A short to ground may also cause multiple Communication Lost DTCs to be set by modules connected to the high speed GMLAN data link.

1. With the ignition off, disconnect the ECM and TCM harness connectors one at a time. After each disconnection, check for current DTCs. DTC U1814 should remain current.
• If the DTC is transferred to the history, replace the controller that was disconnected before the DTC was transferred to the history.
2. Turn off ignition, disconnect the wiring harness connector at the BCM.
3. Check for infinite resistance between the serial communication line wake-up auxiliary circuit and ground.
• If the resistance is not infinite, eliminate the short to ground in the serial communication line circuit.
4. If everything is OK, replace the BCM controller.

Chain	Short to ground	Open circuit or increased resistance	Short circuit to supply voltage	Signal characteristics
Enabling the serial communication line	U2099, U0100 - U0299?	U0100 - U0299	U0100 - U0299?	-
? The engine does not start. ? History only. When cleared, the fault code returns after a few ignition cycles.

Chain	Normal range	Short to ground	Cliff	Short circuit to supply voltage
Operating conditions: Ignition switch in ACC or RUN position
Enabling the serial communication line	ON	Off	ON	ON
Operating conditions: Ignition switch OFF
Enabling the serial communication line	Off	Off	Off	ON

• The voltage in the system is 9 - 16 V.
• The vehicle power mode master device requires serial data exchange to operate.

• If a fault occurs, the command output is disabled.
• Controllers use the default values of missing parameters until the next ignition cycle.
• The controllers never issued signals, so certain subsystems will not work.
• The engine cannot be started while the circuit is shorted to ground.

• The current fault code is cleared once the fault has disappeared.
• The fault code is cleared from the history when the ignition cycle counter in the controller reaches the reset threshold of 50 without the fault recurring.

• To localize an intermittent fault, use the MIN/MAX function of the multimeter.
• A short to ground will also cause multiple fault codes to be set in the "Communication Loss" log from controllers connected to the high speed GMLAN communication line.

1. Turn ignition off, disconnect the wiring harness connector at the EBCM.
2. Check for current DTCs. DTC U2099 should remain current.
• If the DTC is stored in the history, replace the EBCM.
3. Turn off ignition, disconnect the wiring harness connector at the BCM.
4. Check for infinite resistance between the serial communication line enable circuit and ground.
• If the resistance is not infinite, eliminate the short circuit to ground in the power-on circuit.
5. If everything is OK, replace the BCM controller.

[The article is reprinted from the website: ChevyMan]